长期口服缬沙坦对心肌梗死后室性心律失常的影响 (英文)

目的：探讨长期口服血管紧张素 II的1型受体拮抗剂缬沙坦对兔心肌梗死后室性心律失常发生的影响及其可能机制。方法：24只新西兰大白兔随机分为假手术对照组（n＝8）、心肌梗死组（n＝8）和缬沙坦组（n＝8）。假手术对照组只开胸不结扎左冠状动脉前降支，心肌梗死组和缬沙坦组分别结扎左冠状动脉前降支。缬沙坦组术后第二天用缬沙坦（10 mg·kg^-1·d-1）灌胃，三组共喂养12周。三组分别在心肌梗死前、梗死12周后记录左心室内、中、外层心室肌细胞单相动作电位（MAP），并记录心肌梗死12周后诱发的恶性心律失常次数。结果：1.心肌梗死12周后，缬沙坦组室速/室颤（VT/VF）的发生次数较心肌梗死组显著减少（3.1±0.8）次比（12.7±1.5）次，P＜0.05]；2.心肌梗死组左室三层心肌细胞从MAP起始到复极完成90%的时间（APD90）较心肌梗死前明显延长（259.2±22.1）ms，（288.0±25.8）ms，（244.6±22.6）ms 比（230.1±23.2）ms，（244.2±23.4）ms，（229.0±21.7）ms，P＜0.05或＜0.01]；缬沙坦组左室三层心肌细胞APD90与心肌梗死前相比没有明显差异（P 均＞0.05）；且心肌梗死组跨壁复极离散度（TDR）较假手术对照组、缬沙坦组明显延长（37.2±10.2）比（18.8±6.2）比（23.9±7.7），P＜0.05或＜0.01]；缬沙坦组与假手术对照组之间 TDR比较无显著性差异（P＞0.05）。结论：长期口服缬沙坦明显降低兔心肌梗死后恶性室性心律失常的发生次数，这可能与改善兔心肌梗死后跨壁复极离散度有关。

Influence of long-term oral valsartan on ventricular arrhythmia after myocardial infarction in rabbits

Objective：To explore influence of long-term oral valsartan-angiotensin II type 1 receptor blocker on ventricular arrhythmia after myocardial infarction （MI）in rabbits and its possible mechanism.Methods：A total of 24 NeW Zealand rabbits Were randomly divided into sham operation group （n=8）,MI group （n=8）and valsartan group （n=8）according to number table.Sham operation group only received thoracotomy Without ligation of ante-rior descending branch of left coronary artery （LAD）,While MI group and valsartan group received ligation of ante-rior descending branch of LAD.Valsartan group received valsartan gavage （10 mg·kg^-1·d-1 ）since the second day after operation,three groups all Were fed for 1 2 Weeks.Mono active potential （MAP）of left ventricular myo-cardial cells of subendocardial myocardium （inner layer myocardium）,subepicardial myocardium （outer layer myo-cardium） and middle layer myocardium Were recorded before MI and 1 2 Weeks after MI,and times of provocative malignant arrhythmias Were recorded on 1 2 Weeks after MI in three groups.Results：1. Ventricular tachycardia or fibrillation （VT/VF）episodes Were markedly decreased in VAL group than that in MI group on 1 2 Weeks after MI （3.1±0.8）vs.（12.7±1.5）,P〈0.05];2. After MI 12 W,the action potential duration to 90% repolarization （APD90）of three-layer ventricular myocytes in MI group Was prolonged than that before MI （259.2±22.1）ms, （288.0±25.8）ms,（244.6±22.6）ms vs.（230.1±23.2）ms,（244.2±23.4）ms,（229.0±21.7）ms,P〉0.05 or 〉0.01];but there Were no significant difference in APD90 of three layers ventricular myocytes betWeen before and af-ter MI in valsartan group （P〉0.05 all）;Compared With sham operation group and valsartan group,there Was sig-nificant prolonged in transmural dispersion of repolarization （TDR）（18.8±6.2）vs.（23.9±7.7）vs.（37.2± 10.2）,P〈0.05 or 〈0.01]in MI group;There Was no significant difference in TDR betWeen valsartan group and sham operation group （P〉0.05）.Conclusion：Long-term oral valsartan can significantly reduce malignant ventricu-lar arrhythmia incidence in rabbits after MI,Which may be related to improving TDR in rabbits after MI.